Fireproof member and fireproof coating material including same

Abstract

Provided are a fireproof member and a fireproof coating material constituted of wood that are capable of imparting fire extinguishing / spread suppression performance. This fire-resistant member and the fire-resistant coating material including the fire-resistant member are characterized by using wood impregnated with a fire extinguishing / spread suppressing agent composition for suppressing spread of a fire by coating a combustion product at a high temperature, and generating a radical having a quenching effect due to a negative catalyst effect during combustion to extinguish a fire.

Description

Fire-resistant member and fire-resistant covering material containing same

[0001] The present invention relates to a fire-resistant member and a fire-resistant covering material including the same.

[0002] Fire extinguishing compositions that generate an aerosol upon combustion to extinguish or suppress a fire are known (see, for example, Patent Document 1). Such fire extinguishing compositions can be used as solids, such as powders or molded bodies of a desired shape.

[0003] In addition, a fire-extinguishing and fire-suppressing composition containing a phosphorus salt, a potassium salt, and a dispersion medium, which has a low environmental impact and is suitable for extinguishing large-scale fires such as forest fires and suppressing the spread of fires (preventing re-ignition) is known (see, for example, Patent Document 2). Such a fire-extinguishing and fire-suppressing composition can be used against forest fires, for example, by being contained in a container made of a biodegradable plastic.

[0004] International Publication No. WO2017 / 134703 International Publication No. WO2021 / 181957

[0005] The molded article described in Patent Document 1 above can be said to be a so-called self-extinguishing molded article, and while there is room for use in applications such as imparting or improving fire extinguishing performance to an object to be protected, there is still room for improvement when it comes to use as, for example, a building component.

[0006] The fire-extinguishing and fire-spread retardant composition described in Patent Document 2 contributes not only to extinguishing burning materials (mainly wood) in forest fires but also to preventing the spread of fire. However, when carrying out firefighting activities, the fire-extinguishing and fire-spread retardant composition needs to be stored in a container and injected or dropped into the area to be extinguished.

[0007] Therefore, an object of the present invention is to provide a fire-resistant component and a fire-resistant covering material containing the same, which are made of wood that can be used as a building component and which can impart fire extinguishing and fire spread suppression properties to the wood itself.

[0008] In order to solve the above-mentioned problems, the present invention provides a fire-resistant member made of wood impregnated with a fire-extinguishing and fire-spread retardant composition that covers burning materials at high temperatures to suppress the spread of fire and generates radicals that have a flame-extinguishing effect due to a negative catalytic effect during combustion, thereby extinguishing and suppressing fires.

[0009] In the fire-resistant member of the present invention, the fire extinguishing and fire spread suppressant composition preferably contains a phosphorus salt, a potassium salt, and a dispersion medium. Furthermore, the phosphorus salt preferably contains ammonium monophosphate and ammonium diphosphate. The potassium salt is preferably a compound that generates potassium radicals by thermal energy during combustion. Furthermore, the dispersant preferably contains water.

[0010] Furthermore, the fire-extinguishing and fire-spread suppressant composition for the fire-resistant member of the present invention having the above-described configuration preferably contains 5 to 30 mass% of the phosphorus salt and 0.1 to 25 mass% of the potassium salt. The remainder may be a dispersion medium and other optional additives. It goes without saying that the total of all components of the fire-extinguishing and fire-spread suppressant composition is 100 mass%.

[0011] The present invention also provides a fire-resistant covering material comprising an object to be protected and the fire-resistant member of the present invention that covers the periphery of the object to be protected.

[0012] According to the present invention, it is possible to provide a fire-resistant component and a fire-resistant covering material containing the same, which are made of wood that can be used as a building component and which can be given fire extinguishing and fire spread suppression properties to the wood itself.

[0013] FIG. 1 is a schematic diagram of a fire-resistant coating material 1 according to the present embodiment. FIG. 2 is a schematic diagram of a fire-resistant coating material 11 according to a first modified example of the present embodiment. FIG. 3 is a schematic diagram of a fire-resistant coating material 21 according to a second modified example of the present embodiment. FIG. 4 is a diagram showing an outline of a test specimen T used in a fire resistance test. FIG. 5 is a diagram showing temperature measurement positions in a fire resistance test. FIG. 6 is a front view, a B-B' cross-sectional view, and a C-C' cross-sectional view showing an outline of a testing furnace. FIG. 7 is a graph showing measurement results of heating temperatures in a fire resistance test. FIG. 8 is a graph showing measurement results of surface temperatures of load-supporting members in a fire resistance test.

[0014] Representative embodiments of the fire-resistant component and fire-resistant covering material according to the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to these drawings. Furthermore, since the drawings are intended to conceptually explain the present invention, the dimensions, ratios, and numbers may be exaggerated or simplified for ease of understanding.

[0015] In this embodiment, it is assumed that the fire-resistant member according to the present invention is used as a fire-resistant covering material. However, the fire-resistant member may also be used for other purposes, such as a wall material or a ceiling material.

[0016] As illustrated in FIG. 1 , the fire-resistant covering material 1 of this embodiment includes stacked fire-resistant members 3 and 5 that cover the periphery of the object to be protected (covered object) 9. However, the fire-resistant covering material 1 may be composed solely of the fire-resistant member 5. The object to be protected 9 is assumed to be, for example, a load-bearing member such as a pillar or a beam, but is not limited thereto. These load-bearing members such as pillars and beams may be made of wood, metal, or a composite material thereof. For example, the fire-resistant covering material 11 according to Modification 1 of this embodiment protects a beam as the object to be protected 9. The fire-resistant covering material 1 may cover the entire periphery (all sides) of the object to be protected 9 (see FIGS. 1 and 2 ), or may cover only a portion of the periphery (side) of the object to be protected 9 (see FIG. 3 ). For example, the fire-resistant covering material 21 according to Modification 2 of this embodiment partially covers a beam as the object to be protected 9 (leaving one side of the angular beam exposed). Of course, both end faces of the object to be protected 9 may also be covered.

[0017] Suitable wood materials for use as load-bearing members include natural wood materials such as cedar, larch, cypress, and Japanese cypress. Artificial wood materials, such as molded wood obtained by molding plywood or chips, and composite wood materials of natural wood and artificial wood materials are also suitable. Examples of artificial wood materials include hardboard, fiberboards such as medium-density fiberboard (MDF) and soft fiberboard (insulation board), and particleboard. The shapes of lumber materials used as load-bearing members include, for example, board-like, rectangular, cylindrical, cubic, rectangular, and spherical. In the case of artificial wood materials and composite wood materials, more complex shapes are also possible in addition to the above shapes.

[0018] The fire-resistant member 5 is located on the outer surface side of the fire-resistant covering material 1, and the fire-resistant member 3 is interposed between the fire-resistant member 5 and the object to be protected 9. Furthermore, separate members (layers of metal materials, adhesives, etc.) may be interposed between the fire-resistant members 3 and 5, and between the fire-resistant member 3 and the object to be protected 9. In this embodiment, wood impregnated with different fire-extinguishing and fire-spread suppressant compositions (hereinafter also referred to as "agents" or "fire-extinguishing agents" in this specification) is used as the fire-resistant members 3 and 5. However, the wood serving as the base material for the fire-resistant members 3 and 5 may be impregnated with the same agent. The wood serving as the base material for the fire-resistant members 3 and 5 may be the same or different tree species. Below, the fire-resistant member 5 will be described in detail, followed by the fire-resistant member 3.

[0019] The fire-resistant member 5 is made of wood impregnated with a fire-extinguishing and fire-spread retardant composition. Natural wood such as cedar, larch, cypress, and Japanese cypress is suitable as the base material of the fire-resistant member 5, but artificial wood or composite wood may also be used as long as it can be impregnated with the agent. The base material is preferably plate-shaped, but may also be angular, cylindrical, cubic, rectangular, spherical, or other shapes. The fire-resistant member 5 may be a single layer or may be multi-layered.

[0020] The fire-extinguishing and fire-spread retardant composition is a composition that has the function of suppressing fires by generating radicals that have a flame-extinguishing effect due to a negative catalytic effect upon combustion. The fire-extinguishing and fire-spread retardant composition can be impregnated into the fire-resistant member 5 by, for example, impregnating the base material with an aqueous solution (fire-extinguishing agent) containing 20% ​​by mass of potassium salt and 5% by mass of phosphorus salt using a known method such as vacuum impregnation or vacuum pressure impregnation. Furthermore, during impregnation with the agent, the base material may be subjected to an insizing treatment using a drill or nail.

[0021] The fire extinguishing and fire spread suppressant composition of the present invention will be described in detail below. However, the present invention is not limited to these, and various variations are conceivable within the scope of the technical concept of the present invention, all of which are included in the present invention.

[0022] <Fire-extinguishing and fire-spread suppressant composition> The fire-extinguishing and fire-spread suppressant composition according to the present invention is characterized by mainly containing (A) a phosphorus salt, (B) a potassium salt, and (C) a dispersion medium. These components will be described below.

[0023] (A) Phosphate Phosphate has the effect of preventing rekindling due to carbonization of the wood surface. Examples of phosphorus salts include ammonium phosphate such as monobasic ammonium phosphate, dibasic ammonium phosphate, and tribasic ammonium phosphate, sodium phosphate such as monobasic sodium phosphate, dibasic sodium phosphate, and tribasic sodium phosphate, potassium phosphate such as monobasic potassium phosphate, dibasic potassium phosphate, and tribasic potassium phosphate, phosphoric acids, guanyl phosphate, urea phosphate, amide phosphoric acid, phosphate esters, and dimethyl phosphate.

[0024] Among these, ammonium salts of phosphoric acid are preferred from the viewpoint of their high fire spread prevention effect of covering objects that are burning materials (materials to be extinguished) at high temperatures (for example, about 190°C or higher), and it is further preferred to use ammonium monophosphate and ammonium diphosphate in combination.

[0025] The content of the phosphorus salt in the fire extinguishing and fire spread suppressant composition of the present invention is preferably as high as possible, since the effect is higher as the content is higher, but from the viewpoints of handling and sprayability, the maximum amount that allows the composition to remain in the state of an aqueous solution is preferred. For example, the content may be 5 to 40 mass %, and more preferably 5 to 30 mass %.

[0026] When ammonium monophosphate and ammonium diphosphate are used in combination as the phosphorus salts, the mixing ratio of ammonium monophosphate:ammonium diphosphate may be 1-3:1-10 by mass, and preferably 1-3:2-8.

[0027] (B) Potassium Salts Potassium salts are compounds that generate potassium radicals when exposed to thermal energy, and improve anti-inflammatory properties through the negative catalytic effect of the potassium radicals. Examples of potassium salts include potassium nitrate, potassium sulfate, potassium hydroxide, potassium acetate, potassium propionate, monopotassium citrate, dipotassium citrate, tripotassium citrate, monopotassium trihydrogen ethylenediaminetetraacetate, dipotassium dihydrogen ethylenediaminetetraacetate, tripotassium monohydrogen ethylenediaminetetraacetate, tetrapotassium ethylenediaminetetraacetate, potassium hydrogen phthalate, dipotassium phthalate, potassium hydrogen oxalate, dipotassium oxalate, and potassium bicarbonate.

[0028] Among these, potassium bicarbonate or tripotassium citrate is preferably used from the viewpoint of a water-soluble potassium-containing compound to be used in an aerosol fire extinguishing agent.

[0029] The content of the potassium salt in the fire extinguishing and fire spread suppressant composition of the present invention may be 0.1 to 25 mass %, and more preferably 20 to 25 mass %, from the viewpoint that a larger aerosol generation amount and solubility are desirable.

[0030] (C) Dispersion medium The dispersion medium contains the phosphorus salt (A) and the potassium salt (B) dispersed or dissolved therein and also exhibits a cooling effect. Examples of such dispersion medium include water (including all transparent liquids commonly called water, such as tap water, filtered water, ion-exchanged water, distilled water, and pure water), seawater, river water, lake water, groundwater, and well water.

[0031] Among these, water is preferred from the viewpoint that it is possible to dissolve a larger amount of the fire-extinguishing components, the phosphorus salt and potassium salt, and it is desirable to have a smaller content of ions, fine particles, etc. so as not to form a solid, etc. The dispersion medium accounts for the remainder of the fire-extinguishing and fire-spread suppressant composition of the present invention other than the phosphorus salt (A), the potassium salt (B), and the optional additive component (D) described below.

[0032] (D) Optional Additives The fire extinguishing and fire spread suppressant composition of the present invention may contain other optional components as long as the effects of the present invention are not significantly impaired. Examples of such optional additives include salts of alkali metals or alkaline earth metals other than potassium, as well as borates, nitrates, silicates, sulfates, etc. The amount of the optional additives may also be within a range that does not significantly impair the effects of the present invention.

[0033] Therefore, in the fire-resistant member 5 of this embodiment, by containing phosphorus salt, when the material becomes hot due to heat from a fire or the like, it can cover the burning material and suppress the spread of the fire, and by containing potassium salt, it can generate radicals that have a flame-extinguishing effect due to a negative catalytic effect during combustion, thereby extinguishing and suppressing the fire.

[0034] By using the fire-resistant member 5 of this embodiment, it is possible to impart fire extinguishing and fire spread suppression performance to a protected object such as a building component. In particular, when the fire-resistant member 5 is laminated as the fire-resistant covering material 1, it is preferable to place it on the outer surface side. This makes it possible to effectively suppress the temperature rise of the inner covering material (fire-resistant member 3) and the protected object.

[0035] More specific methods for impregnating the wood substrate with the fire-extinguishing and fire-spread suppressant composition include contacting at least a portion of the surface of the wood with the fire-extinguishing and fire-spread suppressant composition or immersing the wood in the fire-extinguishing and fire-spread suppressant composition. In the former case, the fire-extinguishing and fire-spread suppressant composition may be in liquid (fluid) form or mist form. To ensure more reliable impregnation, impregnation may be performed under a negative pressure environment using a reduced-pressure impregnation device.

[0036] The degree of impregnation of the wood with the fire extinguishing and fire spread retardant composition can be appropriately selected within a range that achieves the effects of the present invention. However, to more reliably achieve the effects of the present invention, it is ideal to impregnate, for example, 100% of the total surface area of ​​the wood, but for example, 30% or 50% or more may be impregnated. Furthermore, the impregnation depth is ideal, for example, to as deep as possible from the surface of the wood, but it may be impregnated to a depth of more than 0 mm, and more preferably to a depth of 1 mm or more, and even more preferably to a depth of 10 mm or more. The upper limit of the impregnation depth may be appropriately determined depending on the type, condition, and dimensions of the wood. Furthermore, the moisture content may be adjusted by drying after impregnation (for example, an average moisture content of 15% or less, preferably 10% or less).

[0037] Next, the fire-resistant member 3 will be described. The fire-resistant member 3 is made of wood impregnated with a fire-extinguishing agent. Natural wood such as cedar, larch, cypress, and Japanese cypress is suitable as the base material of the fire-resistant member 3, but artificial wood or composite wood may also be used as long as it can be impregnated with the agent. Furthermore, the shape of the fire-resistant member 3 is preferably a plate, but it may also be angular, cylindrical, cubic, rectangular, spherical, or other shapes. Furthermore, the fire-resistant member 3 may be a single layer or may be laminated.

[0038] The impregnation of the refractory member 3 with the agent is carried out by penetrating the base material with a saturated aqueous solution of phosphoric acid by a known method such as vacuum impregnation or vacuum pressure impregnation. In addition, when impregnating the agent, the base material may be subjected to an incising treatment using a drill or nails.

[0039] The saturated aqueous solution of phosphoric acid is an aqueous solution containing 30% by mass of phosphoric acid. The phosphoric acid may be orthophosphoric acid, diphosphoric acid, polyphosphoric acid, metaphosphoric acid, or the like.

[0040] By using the fire-resistant member 3, the covering material placed near the object to be protected 9 can contain a lot of phosphorus, such as a saturated aqueous solution of phosphoric acid, and can prevent the fire from spreading to the interior. On the other hand, for covering materials located far from the object to be protected 9, i.e., on the outside and directly exposed to the heat of the flames, it is preferable to mix a large amount of potassium, which has a fire-extinguishing effect, such as 20% to 25% potassium + 5% phosphoric acid.

[0041] Fire Resistance Test As described below, the fire-resistant members 3 and 5 were wrapped around the load-supporting member, which was the object to be protected 9, to prepare a test specimen T, and a fire resistance test was carried out.

[0042] The fire-resistant members 3 and 5 were prepared as follows. The prepared wood was of two dimensions: 30 mm thick or 20 mm x 170 mm wide x 650 mm long, with and without insizing treatment. (1) The wood (cedar and larch) was impregnated with the following two chemicals using a vacuum-pressure impregnation device: (a) saturated aqueous solution of phosphoric acid (30% phosphoric acid) (b) aqueous solution of 20% potassium salt and 5% phosphorus salt (2) The moisture content of the wood was reduced to 20% or less using an artificial dryer.

[0043] The fire-resistant components prepared as described above were impregnated with chemicals over 100% of the total surface area of ​​the wood and then dried until the average moisture content was 15% or less. As a result, in Tests 1 to 6 in Table 1 below, approximately 700 to 850 g of the solid components of the (b) chemical solution were impregnated for cedar and approximately 250 to 600 g for larch. In Test No. 7, approximately 800 to 950 g of the solid components of the (a) chemical solution and approximately 690 to 710 g of the solid components of the (b) chemical solution were impregnated. In Test No. 8, approximately 590 to 620 g of the solid components of the (a) chemical solution and approximately 460 to 520 g of the solid components of the (b) chemical solution were impregnated.

[0044] The prepared fire-resistant members 3 and 5 were attached to a load-bearing member (cedar, cross-sectional dimensions 120 mm x 120 mm) in accordance with Table 1 below, and this was designated as test specimen T. (a) Tests 1 to 6: [20% potassium salt + 5% phosphorus salt aqueous solution] 30 mm thick x 3 sheets: total thickness 90 mm (b) Test 7: Inside: [saturated phosphorus salt aqueous solution] 30 mm thick x 2 sheets Outside: [20% potassium salt + 5% phosphorus salt aqueous solution] 30 mm thick x 1 sheet Total 3 sheets: total thickness 90 mm (c) Test 8: Inside: [saturated phosphorus salt aqueous solution] 20 mm thick x 3 sheets Outside: [20% potassium salt + 5% phosphorus salt aqueous solution] 20 mm thick x 1 sheet Total 4 sheets: total thickness 80 mm Note that carbonization of the load-bearing member was confirmed in Tests 1 and 2. Since the carbonization of the load-bearing members was thought to be caused by heat entering through opening of the joints at the corners, in test 3 and onwards, the opening of the joints at the corners of the fire-resistant members 3 and 5 was addressed by making the pitch of the fastening screws of the fire-resistant members 3 and 5 finer, using adhesive, and applying aluminum tape to the joints at the corners.

[0045] The specifications of test specimen T are shown in Figure 4. The temperature measurement positions on test specimen T are shown in Figure 5. Using this test specimen T, tests 1 and 2, tests 3 and 4, tests 5 and 6, and tests 7 and 8 were each carried out simultaneously. Reinforced gypsum board C was installed in the areas other than fire-resistant members 3 and 5, and the outer surface was covered with BSSR blanket B.

[0046] A one-hour fire resistance test was then conducted in a small-scale test furnace, the schematic of which is shown in Figure 6. Specifically, as shown in Figure 7, the specimens were heated for one hour according to the standard heating curve (following formula) specified in ISO 834-1, followed by 240 minutes of cooling in the furnace. T = 345 log 10 (8t + 1) + 20, where T is the average furnace temperature (°C), and t is the elapsed time of the test (minutes). The surface temperature of the load-bearing members was measured, as shown in Figure 8. The symbols L1 to L12 in Figures 8(A) and 8(B) correspond to the symbols L1 to L12 in Figures 5(A) and 5(B).

[0047] After cooling, the coating material was removed and the carbonization of the load-bearing member and the fire-resistant coating material were checked. However, in tests 5 and 6, the samples were removed from the furnace immediately after heating in order to check the carbonization depth of the coating material immediately after heating. The pass criterion was that there was no carbonization of the load-bearing member. The test conditions and test results are as follows:

[0048]

[0049] As can be seen from Table 1, by using the fire-resistant member 5 according to this embodiment as the fire-resistant coating material 1 (or a part thereof), it was possible to effectively suppress carbonization of the load-bearing member, which is the object to be protected 9. One of the factors contributing to this result is that the fire spread suppression effect of the phosphorus salt contained in the fire extinguishing and fire spread suppressant composition in the fire-resistant member and the flame-extinguishing effect of the potassium salt sufficiently suppressed the temperature rise on the surface of the load-bearing member.

[0050] Although typical embodiments of the present invention have been described above, the present invention is not limited to these, and various design modifications are possible, which are also included in the present invention.

[0051] 1, 11, 21 Fireproof covering material 3, 5 Fireproof member 9 Target to be protected

Claims

1. A fire extinguishing and fire retardant composition impregnated into the wood, The fire extinguishing and fire spread retardant composition covers burning materials at high temperatures to suppress the spread of fire, and generates radicals having a flame-extinguishing effect due to a negative catalytic effect during combustion, thereby extinguishing or suppressing fires. A fire-resistant member characterized by:

2. The fire extinguishing and fire spread suppressant composition contains a phosphorus salt, a potassium salt, and a dispersion medium; The fire-resistant member according to claim 1 ,

3. the phosphorus salts include ammonium phosphate monobasic and ammonium phosphate dibasic; 3. The fire-resistant member according to claim 2, wherein:

4. the potassium salt is a compound that generates potassium radicals by thermal energy upon combustion; 4. The fire-resistant member according to claim 2 or 3,

5. the dispersion medium contains water; 4. The fire-resistant member according to claim 2 or 3,

6. The phosphorus salt is contained in an amount of 5 to 30% by mass, and the potassium salt is contained in an amount of 0.1 to 25% by mass.

4. The fire-resistant member according to claim 2 or 3,

7. The object of protection, The fire-resistant member according to claim 1 which covers the periphery of the object to be protected. A fire-resistant coating material characterized by:

8. The fire-resistant member includes a plurality of the fire-resistant members, Aluminum tape is attached to at least a part of the joints between the fire-resistant members; The fire-resistant coating material according to claim 7, characterized in that